A web winding machine is known in which a toothed perforated web cutting device is inserted from below and between support rollers, when these have been stopped, and into a wedge-shaped space formed between the support rollers and the spool on which the web material is wound. The web cutting device is pressed against the web at a place where it is looped part of the way around one of the support rollers. Hence, when a wound, finished roll of the web is subsequently lifted away from the one support roller over the second support roller, the web is torn off against the toothed web cutting device, along its line of perforations. During this severance, the arriving leading segment of the web is firmly held onto the roller via bores in the roller casing, by maintaining inside the support roller a low pressure which is transmitted to one side of the web through bores in the casing of the roller (see German Laid-Open Patent Application Specification No. 29 20 707).
This known arrangement for severing a web has a serious disadvantage introduced by pressing the toothed perforating web tearing device against the support roller thereby not only blunting the toothed perforating device, but in time also damaging the surface of the support roller.